text: Foraminifera are widely used for paleoclimatic and paleoceanographic research because of the oxygen isotopes in their calcium carbonate shells. Oxygen isotopes, or δO, are used to interpret past temperature and ice volume. Foraminifera also incorporate trace amounts of boron in their shells, which is used to reconstruct past pH. Foraminiferal isotopic composition is affected by factors such as algal symbionts or species-specific physiology. The influence of such vital effects can be determined via culture experiments.